Study On The Technology Of Measurement And Control System For Inspection Of Curved Micro-pipe

There are many small size pipes widely used in industrial fields, ranging from petrochemical industry to nuclear industry. Those small pipes are playing a very important role in the place where it is applied. Sometimes, a tiny leak in pipe may cause a big problem, even a disaster. In this dissertation, we introduced a MEMS-based in-pipe inspection system. This kind of in-pipe inspection system is designed for the 3D pipe of 10mm diameter. It is composed of piezoelectric ceramic actuator, moving distance measurement device , pipe geometry characteristics measurement device, and in-pipe surface detector.In chapter 1, the history and tendency about the technology of micro-robot & micro-pipe inspection system are introduced. The significance of the project studied by our lab and the contents of this dissertation are summarized.In chapter 2, in order to make the piezoelectric ceramic actuator work in the optimum status , it requires the driving voltage should be less than ±70V, the driving frequency should be about 1KHz, and duty ratio should be about 50%. In addition, all those parameters can be adjustable in a certain range. So we designed a kind of driving circuit to meet the requirement of the actuator driving. In order to get the data of how long does the micro-robot go, we designed moving distance measurement device which can counter the steps that the micro-robot makes , so that we can calculate the distance with the steps.In chapter 3 , based on the characteristics of 3D curved micro-pipe, the solutions of the pipe geometry characteristics inspection are introduced, and the related circuit for controlling and driving the pipe geometry characteristics measurement device is designed.In chapter 4, the in-pipe surface detector are based on LD(Laser Diode)light source—PSD(Position Sensitive Detector)that is the core component in this inspection system. The solutions to drive and control this device are introduced.In chapter 5, in order to ensure the whole system working in steadycondition, the solutions to lower the interferences coming from the outside and inside of the system are introduced.Last chapter summarized the work of this dissertation, and future work of this dissertation were also sketched out.